diff --git a/Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp b/Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp
index a00ac38..6e6d4c4 100644
--- a/Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp
+++ b/Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp
@@ -17982,6 +17982,25 @@ bool RunCoreWorldActorIntegrationTest(const FExploreArguments& Arguments, FStrin
             OutError = TEXT("Could not create the BuildHost stream-trace pawn.");
             return false;
         }
+        FVector StartupTraceSpawnCm = FVector::ZeroVector;
+        FString StartupTraceSpawnText;
+        if (FParse::Value(FCommandLine::Get(), TEXT("voxel.StartupTraceSpawnCm="),
+                          StartupTraceSpawnText, false))
+        {
+            TArray<FString> Components;
+            StartupTraceSpawnText.ParseIntoArray(Components, TEXT(","), true);
+            if (Components.Num() != 3
+                || !LexTryParseString(StartupTraceSpawnCm.X, *Components[0])
+                || !LexTryParseString(StartupTraceSpawnCm.Y, *Components[1])
+                || !LexTryParseString(StartupTraceSpawnCm.Z, *Components[2])
+                || !FMath::IsFinite(StartupTraceSpawnCm.X)
+                || !FMath::IsFinite(StartupTraceSpawnCm.Y)
+                || !FMath::IsFinite(StartupTraceSpawnCm.Z))
+            {
+                OutError = TEXT("voxel.StartupTraceSpawnCm must be finite X,Y,Z centimetres.");
+                return false;
+            }
+        }
         USceneComponent* PawnRoot = NewObject<USceneComponent>(PlayerPawn, NAME_None, RF_Transient);
         if (PawnRoot == nullptr)
         {
@@ -17990,7 +18009,7 @@ bool RunCoreWorldActorIntegrationTest(const FExploreArguments& Arguments, FStrin
         }
         PlayerPawn->SetRootComponent(PawnRoot);
         PawnRoot->RegisterComponent();
-        PlayerPawn->SetActorLocation(FVector::ZeroVector, false, nullptr, ETeleportType::TeleportPhysics);
+        PlayerPawn->SetActorLocation(StartupTraceSpawnCm, false, nullptr, ETeleportType::TeleportPhysics);
         PlayerController->Possess(PlayerPawn);
         if (TestWorld->GetFirstPlayerController() != PlayerController
             || PlayerController->GetPawn() != PlayerPawn)
@@ -18029,6 +18048,11 @@ bool RunCoreWorldActorIntegrationTest(const FExploreArguments& Arguments, FStrin
             return false;
         }
         Actor->SetActorTickEnabled(true);
+        VoxelForgeStartupTrace::RecordEvent(TEXT("trace_spawn_location"), FString::Printf(
+            TEXT("\"location_cm\":[%s,%s,%s]"),
+            *FString::SanitizeFloat(StartupTraceSpawnCm.X),
+            *FString::SanitizeFloat(StartupTraceSpawnCm.Y),
+            *FString::SanitizeFloat(StartupTraceSpawnCm.Z)));
 
         auto DesiredTilesLoaded = [](const AVoxelWorld* World)
         {
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/CaptureOwnerStratesL69.py b/Standalone/Research/WorldAssemblerM3/Linux69/CaptureOwnerStratesL69.py
new file mode 100644
index 0000000..3e4322d
--- /dev/null
+++ b/Standalone/Research/WorldAssemblerM3/Linux69/CaptureOwnerStratesL69.py
@@ -0,0 +1,725 @@
+#!/usr/bin/env python3
+"""Render arrival, departure, and mid-tunnel views for the four-strate owner plan."""
+import json
+import importlib.util
+import argparse
+import math
+import os
+import re
+import struct
+import subprocess
+import time
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+OUT = ROOT / "Saved/Linux/l69"
+BIN = OUT / "bin"
+CAPTURES = Path(__file__).resolve().parent / "captures"
+HEADLESS = OUT / "bin/VoxelForgeCoreHeadless-l69"
+RENDERER = BIN / "VoxelForgeOffscreenCapture-l69"
+PNG_DIR = OUT / "capture-png"
+RECIPE_INPUTS = (
+    ("passage-0-1", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "SurfaceWorld", "upper"),
+    ("passage-1-2", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "FloatingIslands", "upper"),
+    ("passage-2-3", ROOT / "Standalone/data/owner_world.json",
+     "surface-world", "TunnelNetwork", "upper"),
+)
+SUBVOXELS_PER_VOXEL = 256.0
+RING_AUDIT = ROOT / "Standalone/Research/WorldAssemblerM3/Linux32/AuditRingTerraceL32.py"
+spec = importlib.util.spec_from_file_location("ring_profile_l32", RING_AUDIT)
+ring_profile = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(ring_profile)
+
+for directory in (OUT, BIN, PNG_DIR, CAPTURES):
+    directory.mkdir(parents=True, exist_ok=True)
+ENV = os.environ.copy()
+ENV["LP_NUM_THREADS"] = "12"
+ENV["XDG_CACHE_HOME"] = str(OUT / "xdg-cache")
+PARSER = argparse.ArgumentParser(description=__doc__)
+PARSER.add_argument("--scene", choices=[value[0] for value in RECIPE_INPUTS])
+PARSER.add_argument("--view", choices=("arrival-mouth", "departure-mouth", "mid-tunnel"))
+OPTIONS = PARSER.parse_args()
+
+
+def run(name, command):
+    log = OUT / f"capture-{name}.log"
+    wrapped = ["taskset", "-c", "0-11", "prlimit", "--as=6442450944", "--",
+               "timeout", "1740s", *map(str, command)]
+    started = time.monotonic()
+    with log.open("w", encoding="utf-8") as stream:
+        result = subprocess.run(wrapped, cwd=ROOT, env=ENV, stdout=stream,
+                                stderr=subprocess.STDOUT, timeout=1740, check=False)
+    elapsed = time.monotonic() - started
+    print(f"[L69CaptureRun] step={name} elapsed={elapsed:.1f}s exit={result.returncode} log={log}",
+          flush=True)
+    if result.returncode != 0:
+        raise SystemExit(f"{name} failed; see {log}")
+    return log
+
+
+def add(a, b):
+    return tuple(x + y for x, y in zip(a, b))
+
+
+def sub(a, b):
+    return tuple(x - y for x, y in zip(a, b))
+
+
+def mul(a, scale):
+    return tuple(x * scale for x in a)
+
+
+def norm(a):
+    length = math.sqrt(sum(x * x for x in a))
+    if length <= 1.0e-9:
+        raise ValueError("passage has a degenerate camera tangent")
+    return tuple(x / length for x in a)
+
+
+def interpolate_route(points, distance):
+    remaining = max(0.0, distance)
+    for a, b in zip(points, points[1:]):
+        delta = sub(b[0], a[0])
+        length = math.sqrt(sum(x * x for x in delta))
+        if length <= 1.0e-9:
+            continue
+        if remaining <= length:
+            t = remaining / length
+            pos = tuple(a[0][axis] + delta[axis] * t for axis in range(3))
+            radius = a[1] + (b[1] - a[1]) * t
+            return pos, radius
+        remaining -= length
+    return points[-1]
+
+
+def route_frame(points, distance):
+    center, radius = interpolate_route(points, distance)
+    before, _ = interpolate_route(points, max(0.0, distance - 0.25))
+    after, _ = interpolate_route(points, distance + 0.25)
+    tangent = norm(sub(after, before))
+    horizontal = norm((tangent[0], tangent[1], 0.0))
+    side = (-horizontal[1], horizontal[0], 0.0)
+    return center, radius, tangent, side
+
+
+def camera_angles(camera, target):
+    delta = sub(target, camera)
+    horizontal = math.hypot(delta[0], delta[1])
+    yaw = math.degrees(math.atan2(delta[0], delta[1]))
+    pitch = math.degrees(math.atan2(delta[2], horizontal))
+    return yaw, pitch
+
+
+def fmt(values):
+    return ",".join(f"{value:.6f}" for value in values)
+
+
+def load_reference_cameras():
+    log = ROOT / "Saved/Linux/l34/run-capture-standard-set-final-radius3.log"
+    pattern = re.compile(
+        r"^\[L34CaptureCamera\] view=(\S+).*?camera_m=\(([^)]*)\) "
+        r"target_m=\(([^)]*)\) clip=(\S+)", re.M)
+    values = {}
+    for name, camera, target, clip in pattern.findall(
+            log.read_text(encoding="utf-8", errors="replace")):
+        parse = lambda value: tuple(float(part) for part in value.split(","))
+        values[name] = (parse(camera), parse(target), None if clip == "none" else parse(clip))
+    return values
+
+
+REFERENCE_CAMERAS = {}
+
+
+def terrain_surface_near(mesh, x, y, expected_height):
+    bounds = (x - 2.0, x + 2.0, y - 2.0, y + 2.0)
+    _, triangles, _ = ring_profile.read_scene(
+        str(mesh), None, -1.0e9, 1.0e9, bounds)
+    buckets = ring_profile.build_buckets(triangles, True, bounds, cell_size=1.0)
+    hits = []
+    for dy in range(-4, 5):
+        for dx in range(-4, 5):
+            sample_x, sample_y = x + dx * 0.5, y + dy * 0.5
+            hit = ring_profile.sample_surface(buckets, sample_x, sample_y, True, 1.0,
+                                              preferred_height=expected_height)
+            if hit is not None:
+                hits.append((math.hypot(dx * 0.5, dy * 0.5),
+                             abs(hit[0] - expected_height), sample_x, sample_y, hit[0]))
+    if not hits:
+        return None
+    distance, _, sample_x, sample_y, height = min(hits)
+    if distance > 2.0 or abs(height - expected_height) > 8.0:
+        return None
+    return sample_x, sample_y, height
+
+
+def load_layout(name, source, recipe):
+    path = OUT / f"layout-{name}.json"
+    run(f"layout-{name}", [HEADLESS, source, "--workers=12", "--world-assembler-prototype",
+        "--stream-benchmark", "--stream-pipeline", "--force-generate", "--clip-radius=2",
+        "--max-clip-level=0", "--max-level=0", f"--recipe={recipe}",
+        f"--resolved-layout-output={path}", "--resolved-layout-only"])
+    return json.loads(path.read_text(encoding="utf-8"))
+
+
+def q_to_meters(layout):
+    return layout["core_voxel_size_um"] / (SUBVOXELS_PER_VOXEL * 1_000_000.0)
+
+
+def q_position(value, scale):
+    return tuple(float(component) * scale for component in value)
+
+
+def q_route(points, scale):
+    return [(q_position(point["position_q"], scale), point["radius_q"] * scale)
+            for point in points]
+
+
+def vector_length(value):
+    return math.sqrt(sum(component * component for component in value))
+
+
+def unit(value):
+    length = vector_length(value)
+    if length <= 1.0e-9:
+        raise RuntimeError("capture camera direction is degenerate")
+    return tuple(component / length for component in value)
+
+
+def add_scaled(point, direction, scale):
+    return tuple(point[axis] + direction[axis] * scale for axis in range(3))
+
+
+def make_player_views(layout):
+    scale = q_to_meters(layout)
+    passages = {(int(item["upper_strate_index"]), int(item["lower_strate_index"])): item
+                for item in layout["passages"]}
+    p01, p12, p23 = passages[(0, 1)], passages[(1, 2)], passages[(2, 3)]
+    strate0 = next(item for item in layout["strates"] if int(item["strate_index"]) == 0)
+    surface_anchors = [item["values"] for item in strate0.get("anchors", [])
+                       if item.get("kind") == "route_point"]
+    if len(surface_anchors) < 2:
+        raise RuntimeError("strate 0 has no resolved surface arrival route")
+    surface_route = [(q_position(value[:3], scale), value[3] * scale)
+                     for value in surface_anchors]
+
+    route_specs = [
+        (0, surface_route, True, surface_route[-1][0], p01, "upper", False),
+        (1, q_route(p01["control_points"], scale), True,
+         q_position(p01["lower_mouth_q"], scale), p12, "upper", True),
+        (2, q_route(p12["control_points"], scale), True,
+         q_position(p12["lower_mouth_q"], scale), p23, "upper", False),
+        (3, q_route(p23["control_points"], scale), True,
+         q_position(p23["lower_mouth_q"], scale), p23, "lower", True),
+    ]
+    views = {}
+    for strate, source_route, reverse_route, spawn, departure, departure_end, reverse_departure in route_specs:
+        route = list(reversed(source_route)) if reverse_route else list(source_route)
+        if vector_length(sub(route[0][0], spawn)) > 5.0:
+            raise RuntimeError(f"strate {strate} spawn is {vector_length(sub(route[0][0], spawn)):.2f} m from its arrival route")
+        path_length = sum(vector_length(sub(b[0], a[0])) for a, b in zip(route, route[1:]))
+        arrival_target_pos, arrival_target_radius = interpolate_route(route, min(20.0, path_length))
+        arrival_camera = (spawn[0], spawn[1], spawn[2] + 1.6)
+        arrival_target = (arrival_target_pos[0], arrival_target_pos[1],
+                          arrival_target_pos[2] - arrival_target_radius + 1.8)
+        ayaw, apitch = camera_angles(arrival_camera, arrival_target)
+        views[(strate, "arrival")] = {
+            "camera": arrival_camera, "target": arrival_target, "yaw": ayaw,
+            "pitch": apitch, "fov_deg": 90.0,
+            "description": "player eye at the strate arrival, facing into its route"}
+
+        route_distance = min(10.0, path_length * 0.2)
+        route_center, route_radius, _, _ = route_frame(route, route_distance)
+        route_camera = (route_center[0], route_center[1],
+                        route_center[2] - route_radius + 1.6)
+        route_target_pos, route_target_radius = interpolate_route(
+            route, min(path_length, route_distance + 28.0))
+        route_target = (route_target_pos[0], route_target_pos[1],
+                        route_target_pos[2] - route_target_radius + 1.8)
+        ryaw, rpitch = camera_angles(route_camera, route_target)
+        views[(strate, "route")] = {
+            "camera": route_camera, "target": route_target, "yaw": ryaw,
+            "pitch": rpitch, "fov_deg": 90.0,
+            "description": "player-height view along the passage or surface route"}
+
+        mouth_path = q_route(departure["control_points"], scale)
+        if departure_end == "lower":
+            mouth_path.reverse()
+        mouth, mouth_radius, inward, _ = route_frame(mouth_path, 0.0)
+        departure_distance = min(7.4, sum(vector_length(sub(b[0], a[0]))
+            for a, b in zip(mouth_path, mouth_path[1:])))
+        inside, inside_radius, _, _ = route_frame(mouth_path, departure_distance)
+        departure_camera = (inside[0], inside[1], inside[2] - inside_radius + 1.6)
+        outward = mul(inward, -1.0)
+        departure_target = (mouth[0] + outward[0] * 12.0,
+                            mouth[1] + outward[1] * 12.0,
+                            mouth[2] - mouth_radius + 1.8)
+        dyaw, dpitch = camera_angles(departure_camera, departure_target)
+        views[(strate, "departure-mouth")] = {
+            "camera": departure_camera, "target": departure_target,
+            "yaw": dyaw, "pitch": dpitch, "fov_deg": 90.0,
+            "description": f"inside the {departure_end} mouth looking out"}
+
+        overview_camera = (spawn[0] - 12.0, spawn[1] - 16.0, spawn[2] + 70.0)
+        overview_target = (spawn[0], spawn[1], spawn[2] - 4.0)
+        oyaw, opitch = camera_angles(overview_camera, overview_target)
+        views[(strate, "overview")] = {
+            "camera": overview_camera, "target": overview_target,
+            "yaw": oyaw, "pitch": opitch, "fov_deg": 90.0,
+            "description": "overview from 70 m above the arrival"}
+    return views
+
+
+def scene_records(path, include_offsets=False):
+    records = []
+    keys = set()
+    with path.open("rb") as stream:
+        header = stream.read(60)
+        if len(header) != 60 or header[:7] != b"VFMSH00":
+            raise RuntimeError(f"{path} has an invalid mesh header")
+        version, voxel_um, count = struct.unpack_from("<III", header, 8)
+        if version not in (1, 2) or voxel_um == 0:
+            raise RuntimeError(f"{path} has an unsupported mesh header")
+        for _ in range(count):
+            start = stream.tell()
+            key_data = stream.read(16)
+            count_data = stream.read(20)
+            if len(key_data) != 16 or len(count_data) != 20:
+                raise RuntimeError(f"{path} has a truncated tile header")
+            key = struct.unpack("<iiii", key_data)
+            _, _, vertices, indices, masks = struct.unpack("<IIIII", count_data)
+            payload_bytes = vertices * 24 + indices * 4 + masks
+            if version == 2:
+                payload_bytes += vertices * 10
+            stream.seek(payload_bytes, os.SEEK_CUR)
+            end = stream.tell()
+            if end > path.stat().st_size:
+                raise RuntimeError(f"{path} ends inside a tile record")
+            keys.add(key)
+            if include_offsets:
+                records.append((key, start, end))
+        if stream.read(1):
+            raise RuntimeError(f"{path} has trailing data after {count} tiles")
+    return header, voxel_um, keys, records
+
+
+def tile_keys_at(point, keys, voxel_um):
+    voxel_m = voxel_um / 1_000_000.0
+    found = set()
+    for level in range(9):
+        extent = 32.0 * (1 << level) * voxel_m
+        key = (math.floor(point[0] / extent), math.floor(point[1] / extent),
+               math.floor(point[2] / extent), level)
+        if key in keys:
+            found.add(key)
+    return found
+
+
+def frame_basis(yaw, pitch):
+    yaw, pitch = math.radians(yaw), math.radians(pitch)
+    forward = (math.sin(yaw) * math.cos(pitch),
+               math.cos(yaw) * math.cos(pitch), math.sin(pitch))
+    right = (math.cos(yaw), -math.sin(yaw), 0.0)
+    up = (-math.sin(yaw) * math.sin(pitch),
+          -math.cos(yaw) * math.sin(pitch), math.cos(pitch))
+    return unit(forward), unit(right), unit(up)
+
+
+def coverage_audit(camera, yaw, pitch, fov, keys, voxel_um):
+    forward, right, up = frame_basis(yaw, pitch)
+    tan_h = math.tan(math.radians(fov) * 0.5)
+    tan_v = tan_h * 900.0 / 1600.0
+    uncovered = []
+    missing_points = []
+    rays = 0
+    distance_samples = tuple(range(1, 200, 4))
+    for row in range(9):
+        sy = (row / 8.0) * 2.0 - 1.0
+        for column in range(17):
+            sx = (column / 16.0) * 2.0 - 1.0
+            ray = unit(tuple(forward[axis] + right[axis] * sx * tan_h
+                             + up[axis] * sy * tan_v for axis in range(3)))
+            rays += 1
+            for distance in distance_samples:
+                point = add_scaled(camera, ray, distance)
+                if not tile_keys_at(point, keys, voxel_um):
+                    uncovered.append((row, column, distance))
+                    missing_points.append(point)
+    return {"rays": rays, "samples_per_ray": len(distance_samples),
+            "missing_samples": len(uncovered), "first_missing": uncovered[:8],
+            "missing_points": missing_points}
+
+
+def merge_scene_exports(destination, sources):
+    unique = {}
+    reference_header = None
+    reference_version = None
+    reference_voxel_um = None
+    for source in sources:
+        header, voxel_um, _, records = scene_records(source, include_offsets=True)
+        version = struct.unpack_from("<I", header, 8)[0]
+        if reference_header is None:
+            reference_header, reference_version, reference_voxel_um = header, version, voxel_um
+        elif version != reference_version or voxel_um != reference_voxel_um:
+            raise RuntimeError("mesh export fragments use incompatible voxel formats")
+        for record in records:
+            unique.setdefault(record[0], (source, record[1], record[2]))
+
+    merged_header = bytearray(reference_header)
+    struct.pack_into("<I", merged_header, 16, len(unique))
+    temporary = destination.with_suffix(destination.suffix + ".merge-tmp")
+    with temporary.open("wb") as output_stream:
+        output_stream.write(merged_header)
+        for source, start, end in unique.values():
+            with source.open("rb") as input_stream:
+                input_stream.seek(start)
+                remaining = end - start
+                while remaining:
+                    block = input_stream.read(min(1024 * 1024, remaining))
+                    if not block:
+                        raise RuntimeError(f"{source} changed while merging mesh exports")
+                    output_stream.write(block)
+                    remaining -= len(block)
+    os.replace(temporary, destination)
+    return len(unique)
+
+
+def write_truncated_scene(source, destination, header, keys, records, remove_keys):
+    retained = [record for record in records if record[0] not in remove_keys]
+    new_header = bytearray(header)
+    struct.pack_into("<I", new_header, 16, len(retained))
+    with source.open("rb") as input_stream, destination.open("wb") as output_stream:
+        output_stream.write(new_header)
+        for _, start, end in retained:
+            input_stream.seek(start)
+            remaining = end - start
+            while remaining:
+                block = input_stream.read(min(1024 * 1024, remaining))
+                if not block:
+                    raise RuntimeError("source mesh changed while writing the negative control")
+                output_stream.write(block)
+                remaining -= len(block)
+    return {key for key in keys if key not in remove_keys}
+
+
+def run_negative_control(mesh, stem, view, header, voxel_um, keys, records):
+    camera = view["camera"]
+    forward, right, up = frame_basis(view["yaw"], view["pitch"])
+    remove = set()
+    for distance in range(89, 110, 4):
+        center = add_scaled(camera, forward, distance)
+        for side in (-8.0, 0.0, 8.0):
+            for vertical in (-8.0, 0.0, 8.0):
+                point = add_scaled(add_scaled(center, right, side), up, vertical)
+                remove.update(tile_keys_at(point, keys, voxel_um))
+    if not remove:
+        raise RuntimeError("negative-control ray did not intersect any exported tiles")
+    truncated = OUT / "controls" / f"{stem}.truncated.vfmesh"
+    truncated.parent.mkdir(parents=True, exist_ok=True)
+    remaining = write_truncated_scene(mesh, truncated, header, keys, records, remove)
+    audit = coverage_audit(camera, view["yaw"], view["pitch"], view["fov_deg"],
+                           remaining, voxel_um)
+    if audit["missing_samples"] == 0:
+        raise RuntimeError("negative control unexpectedly passed frustum coverage")
+    print(f"[L69NegativeControl] file={truncated.relative_to(ROOT)} removed_tiles={len(remove)} "
+          f"missing_samples={audit['missing_samples']} flagged_before_render=1 status=PASS",
+          flush=True)
+
+
+def export_capture(strate, label, view, negative_control=False):
+    stem = f"strate{strate}-{label}"
+    camera = view["camera"]
+    yaw, pitch = view["yaw"], view["pitch"]
+    mesh = OUT / "meshes" / f"{stem}.vfmesh"
+    png = PNG_DIR / f"{stem}.png"
+    jpg = CAPTURES / f"{stem}.jpg"
+    mesh.parent.mkdir(parents=True, exist_ok=True)
+    source = ROOT / "Standalone/data/owner_world.json"
+    parts = [mesh]
+
+    def export_part(part_name, export_camera):
+        part = mesh if part_name.endswith("-base") else OUT / "mesh-patches" / f"{part_name}.vfmesh"
+        part.parent.mkdir(parents=True, exist_ok=True)
+        run(f"{part_name}-export", [HEADLESS, source, "--workers=12",
+            "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+            "--force-generate", "--clip-radius=3", "--max-clip-level=8", "--max-level=8",
+            "--render-distance-chunks=0", "--mesh-coverage", "--capture-skip-walkability",
+            "--recipe=surface-world",
+            f"--camera={fmt((*export_camera, yaw, pitch))}", f"--mesh-export={part}"])
+        return part
+
+    export_part(f"{stem}-base", camera)
+    header, voxel_um, keys, records = scene_records(mesh, include_offsets=negative_control)
+    audit = coverage_audit(camera, yaw, pitch, view["fov_deg"], keys, voxel_um)
+    patch_index = 0
+    while audit["missing_samples"] and patch_index < 3:
+        patch_index += 1
+        points = audit["missing_points"]
+        patch_camera = tuple(sum(point[axis] for point in points) / len(points)
+                             for axis in range(3))
+        patch_name = f"strate{strate}-{label}-patch{patch_index}"
+        part = export_part(patch_name, patch_camera)
+        parts.append(part)
+        merged_tiles = merge_scene_exports(mesh, parts)
+        print(f"[L69CoveragePatch] view={stem} patch={patch_index} "
+              f"camera_m=({fmt(patch_camera)}) merged_tiles={merged_tiles}", flush=True)
+        header, voxel_um, keys, records = scene_records(mesh, include_offsets=negative_control)
+        audit = coverage_audit(camera, yaw, pitch, view["fov_deg"], keys, voxel_um)
+    print(f"[L69Coverage] view={stem} tiles={len(keys)} rays={audit['rays']} "
+          f"samples_per_ray={audit['samples_per_ray']} distance_m=200 "
+          f"missing_samples={audit['missing_samples']} "
+          f"status={'PASS' if audit['missing_samples'] == 0 else 'FAIL'}", flush=True)
+    if audit["missing_samples"]:
+        raise SystemExit(f"{stem} lacks tile coverage within the 200 m camera frustum: "
+                         f"{audit['first_missing']}")
+    if negative_control:
+        run_negative_control(mesh, stem, view, header, voxel_um, keys, records)
+    print(f"[L69CaptureCamera] view={stem} camera_m=({fmt(camera)}) "
+          f"target_m=({fmt(view['target'])}) yaw={yaw:.3f} pitch={pitch:.3f} "
+          f"fov_deg={view['fov_deg']:.1f} description={view['description']}", flush=True)
+    render = [RENDERER, mesh, png, "--size=1600x900",
+        f"--fov-deg={view['fov_deg']:.1f}", f"--camera-m={fmt(camera)}",
+        f"--yaw-deg={yaw:.6f}", f"--pitch-deg={pitch:.6f}",
+        "--tile-skirts=off", "--shade=readable", "--headlamp=on",
+        "--height-tint=on", "--tile-edges=off"]
+    run(f"{stem}-render", render)
+    run(f"{stem}-jpeg", ["ffmpeg", "-nostdin", "-hide_banner", "-loglevel", "error",
+        "-y", "-i", png, "-frames:v", "1", "-q:v", "3", jpg])
+    size = jpg.stat().st_size if jpg.exists() else 0
+    if not 0 < size <= 300_000:
+        raise SystemExit(f"{jpg.name} is missing or exceeds 300 KB (bytes={size})")
+    print(f"[L69CaptureJPEG] file={jpg.relative_to(ROOT)} bytes={size} status=PASS",
+          flush=True)
+
+
+def main():
+    if not HEADLESS.is_file():
+        raise SystemExit(f"missing current L68 headless binary: {HEADLESS}")
+    if not RENDERER.is_file():
+        raise SystemExit(f"missing L69 offscreen renderer: {RENDERER}")
+    layout = load_layout("owner-four-strate", ROOT / "Standalone/data/owner_world.json",
+                         "surface-world")
+    views = make_player_views(layout)
+    print(f"[L69CapturePlan] strates=4 views={len(views)} frustum_m=200 "
+          f"clip_radius=3 max_clip_level=8 max_tile_level=8 patches=up-to-3", flush=True)
+    first = True
+    for strate in range(4):
+        for label in ("arrival", "route", "departure-mouth", "overview"):
+            export_capture(strate, label, views[(strate, label)], negative_control=first)
+            first = False
+    print(f"[L69CaptureSet] files={len(list(CAPTURES.glob('*.jpg')))} "
+          f"directory={CAPTURES.relative_to(ROOT)} status=PASS", flush=True)
+
+
+if __name__ == "__main__":
+    main()
+
+
+def select_passage(layout, mouth_generator, preferred_side):
+    strata = {int(value["strate_index"]): value for value in layout["strates"]}
+    preferred_candidates = []
+    fallback_candidates = []
+    for passage in layout["passages"]:
+        upper = strata[int(passage["upper_strate_index"])]
+        lower = strata[int(passage["lower_strate_index"])]
+        sides = []
+        if upper["generator_kind"] == mouth_generator:
+            sides.append("upper")
+        if lower["generator_kind"] == mouth_generator:
+            sides.append("lower")
+        if preferred_side in sides:
+            preferred_candidates.append((passage, preferred_side == "lower"))
+        elif sides:
+            fallback_candidates.append((passage, sides[0] == "lower"))
+    candidates = preferred_candidates or fallback_candidates
+    if not candidates:
+        raise RuntimeError(f"no passage mouth in generator {mouth_generator}")
+    return sorted(candidates, key=lambda item: item[0]["stable_id"])[0]
+
+
+def make_views(layout, passage, reverse):
+    q_to_m = layout["core_voxel_size_um"] / (SUBVOXELS_PER_VOXEL * 1_000_000.0)
+    controls = [
+        (tuple(value * q_to_m for value in point["position_q"]),
+         point["radius_q"] * q_to_m)
+        for point in passage["control_points"]
+    ]
+    lower_mouth = tuple(value * q_to_m for value in passage["lower_mouth_q"])
+    lower_index = min(range(len(controls)), key=lambda i: sum(
+        (controls[i][0][axis] - lower_mouth[axis]) ** 2 for axis in range(3)))
+    path = controls[:lower_index + 1]
+    if len(path) < 2:
+        raise RuntimeError(f"{passage['stable_id']} has no mouth-to-mouth route")
+    if reverse:
+        path.reverse()
+    lengths = [math.sqrt(sum((b[0][axis] - a[0][axis]) ** 2 for axis in range(3)))
+               for a, b in zip(path, path[1:])]
+    total = sum(lengths)
+    upper, upper_radius, upper_tangent, upper_side = route_frame(path, 0.0)
+    lower, lower_radius, lower_tangent, lower_side = route_frame(path, total)
+    middle_distance = max(12.0, min(total - 12.0, total * 0.4)) if total > 24.0 else total * 0.4
+    if (int(passage["upper_strate_index"],) == 1
+            and int(passage["lower_strate_index"]) == 2 and not reverse):
+        # The old 7 m authored-radius beat sat near the middle of this audit window.
+        middle_distance = min(total - 12.0, 90.8)
+    entry_distance = min(6.0, total * 0.25)
+    entry, entry_radius, entry_tangent, entry_side = route_frame(path, entry_distance)
+    middle, middle_radius, middle_tangent, middle_side = route_frame(path, middle_distance)
+
+    def exterior_view(prefix, center, radius, outward, target):
+        horizontal_outward = norm((outward[0], outward[1], 0.0))
+        eye_height = center[2] - radius + 1.6
+        eye = (center[0] + horizontal_outward[0] * 5.5,
+               center[1] + horizontal_outward[1] * 5.5,
+               eye_height)
+        yaw, pitch = camera_angles(eye, target)
+        return {"name": prefix, "camera": eye, "yaw": yaw, "pitch": pitch,
+                "target": target, "clip": None, "camera_xy": eye[:2],
+                "focus": center, "mouth": center, "eye_height_z": eye_height}
+
+    entrance, entrance_radius, entrance_tangent = upper, upper_radius, upper_tangent
+    exit_point, exit_radius, exit_tangent = lower, lower_radius, lower_tangent
+    ground_target_pos, ground_target_radius = interpolate_route(path, min(total, 1.0))
+    ground = exterior_view("ground-mouth", entrance, entrance_radius,
+        mul(entrance_tangent, -1.0), (ground_target_pos[0], ground_target_pos[1],
+            ground_target_pos[2] - ground_target_radius + 1.0))
+    ground["focus"] = entrance
+    ground["outside_camera"] = True
+
+    def cutaway_view(prefix, center, radius, tangent, side, distance, target_distance):
+        camera = (center[0] - side[0] * 7.0, center[1] - side[1] * 7.0,
+                  center[2] - radius + 1.6)
+        target_pos, target_radius = interpolate_route(path, target_distance)
+        target = (target_pos[0], target_pos[1],
+                  target_pos[2] - target_radius + 1.6)
+        yaw, pitch = camera_angles(camera, target)
+        plane = (side[0], side[1], 0.0,
+                 -(side[0] * center[0] + side[1] * center[1]))
+        return {"name": prefix, "camera": camera, "yaw": yaw, "pitch": pitch,
+                "target": target, "clip": plane, "camera_xy": camera[:2],
+                "focus": center, "mouth": center}
+
+    def inside_mouth_view(prefix, at_start):
+        endpoint_distance = 0.0 if at_start else total
+        mouth, _, tangent, mouth_side = route_frame(path, endpoint_distance)
+        camera_distance = min(total, 7.4) if at_start else max(0.0, total - 5.5)
+        center, _, _, side = route_frame(path, camera_distance)
+        camera = (center[0] + side[0] * 2.5,
+                  center[1] + side[1] * 2.5, center[2])
+        outward = mul(tangent, -1.0) if at_start else tangent
+        target = (mouth[0] + outward[0] * 8.0 + mouth_side[0] * 2.5,
+                  mouth[1] + outward[1] * 8.0 + mouth_side[1] * 2.5,
+                  mouth[2])
+        yaw, pitch = camera_angles(camera, target)
+        return {"name": prefix, "camera": camera, "yaw": yaw, "pitch": pitch,
+            "target": target, "clip": None, "camera_xy": camera[:2],
+            "focus": mouth, "mouth": mouth, "outside_camera": False,
+            "camera_location": "passage-air", "focus_radius": 30.0,
+            "eye_height_z": camera[2], "fov_deg": 80.0}
+
+    # Place each interface view at its true route endpoint. The endpoint camera
+    # is a side cutaway so the solid terrain in front of an underground mouth
+    # cannot hide the floor-to-tunnel connection.
+    arrival_distance = 0.0
+    arrival_center, arrival_radius, arrival_tangent, arrival_side = route_frame(
+        path, arrival_distance)
+    arrival = cutaway_view("arrival", arrival_center, arrival_radius,
+        arrival_tangent, arrival_side, arrival_distance,
+        min(total, arrival_distance + 12.0))
+    arrival["camera_location"] = "passage-air"
+    arrival["focus_radius"] = 20.0
+    arrival["yaw"], arrival["pitch"] = camera_angles(
+        arrival["camera"], arrival["target"])
+
+    entry_camera_distance = min(8.0, total * 0.1)
+    entry_center, entry_radius, entry_tangent, entry_side = route_frame(
+        path, entry_camera_distance)
+    # Player-height view from just inside the passage, aimed through its actual
+    # interface mouth so the floor, bore, and opening share one frame.
+    entry_camera = (entry_center[0], entry_center[1],
+        entry_center[2] - entry_radius + 1.6)
+    entry_target_pos, entry_target_radius = interpolate_route(
+        path, min(total, entry_distance + 14.0))
+    entry_target = (entry_target_pos[0], entry_target_pos[1],
+        entry_camera[2] - 2.5)
+    entry_yaw, entry_pitch = camera_angles(entry_camera, entry_target)
+    entry_view = {"name": "rock-entry", "camera": entry_camera,
+        "yaw": entry_yaw, "pitch": entry_pitch, "target": entry_target,
+        "clip": None, "camera_xy": entry_camera[:2],
+        "focus": entry_center, "mouth": entrance, "outside_camera": False,
+        "camera_location": "passage-air", "focus_radius": 20.0,
+        "eye_height_z": entry_camera[2]}
+    middle_view = cutaway_view("mid-tunnel", middle, middle_radius, middle_tangent,
+        middle_side, middle_distance, min(total, middle_distance + 2.0))
+    ground["focus_radius"] = 20.0
+    middle_view["focus_radius"] = 20.0
+    middle_camera_center, _ = interpolate_route(path, middle_distance)
+    middle_view["camera"] = (middle_camera_center[0] + middle_side[0] * 0.75,
+        middle_camera_center[1] + middle_side[1] * 0.75,
+        middle[2] - middle_radius + 1.6)
+    middle_target_pos, middle_target_radius = interpolate_route(
+        path, min(total, middle_distance + 14.0))
+    middle_view["target"] = (middle_target_pos[0] + middle_side[0] * 2.35,
+        middle_target_pos[1] + middle_side[1] * 2.35,
+        middle_target_pos[2] - middle_target_radius + 1.8)
+    # Keep the camera inside the bore, close to one wall, and look down the
+    # route so the old beat location is visible at player height.
+    middle_view["clip"] = None
+    middle_view["camera_location"] = "passage-air"
+    middle_view["yaw"], middle_view["pitch"] = camera_angles(
+        middle_view["camera"], middle_view["target"])
+    return (ground, entry_view, middle_view, arrival,
+            inside_mouth_view("inside-mouth-start", True),
+            inside_mouth_view("inside-mouth-end", False)), total, lower_index
+
+
+def export_capture(scene_name, source, recipe, passage, endpoint, view):
+    stem = f"{passage['stable_id'].replace('/', '-')}-{endpoint}"
+    view["name"] = stem
+    mesh = OUT / f"{stem}.vfmesh"
+    png = PNG_DIR / f"{stem}.png"
+    jpg = CAPTURES / f"{stem}.jpg"
+    yaw, pitch = view["yaw"], view["pitch"]
+    camera = view["camera"]
+    export_camera = view.get("focus", camera)
+    run(f"{stem}-export", [HEADLESS, source, "--workers=12",
+        "--world-assembler-prototype", "--stream-benchmark", "--stream-pipeline",
+        "--force-generate", "--clip-radius=3", "--max-clip-level=0", "--max-level=0",
+        "--render-distance-chunks=0", f"--recipe={recipe}",
+        f"--camera={fmt((*export_camera, yaw, pitch))}", f"--mesh-export={mesh}"])
+    render_clip = view["clip"]
+    surface = None
+    if view.get("outside_camera", False):
+        surface = terrain_surface_near(mesh, *view["camera_xy"], view["target"][2])
+        if surface is None:
+            camera = (view["camera_xy"][0], view["camera_xy"][1], view["eye_height_z"])
+        else:
+            camera = (surface[0], surface[1], surface[2] + 1.6)
+    elif render_clip is not None:
+        camera = view["camera"]
+    yaw, pitch = camera_angles(camera, view["target"])
+    fov_deg = view.get("fov_deg", 80.0)
+    print(f"[L68CaptureCamera] view={stem} camera_m=({fmt(camera)}) "
+        f"target_m=({fmt(view['target'])}) "
+        f"clip={fmt(render_clip) if render_clip is not None else 'none'} fov_deg={fov_deg:.1f}",
+        flush=True)
+    render = [RENDERER, mesh, png, "--size=1600x900", f"--fov-deg={fov_deg:.1f}",
+        f"--camera-m={fmt(camera)}", f"--yaw-deg={yaw:.6f}", f"--pitch-deg={pitch:.6f}",
+        "--tile-skirts=off", "--shade=readable", "--headlamp=on", "--height-tint=on",
+        f"--height-center-m={view['target'][2]:.6f}", "--height-range-m=8", "--tile-edges=off"]
+    if view.get("focus_radius", 24.0) is not None:
+        render.append(f"--focus-region={fmt((*view['focus'], view.get('focus_radius', 24.0)))}")
+    if render_clip is not None:
+        render.append(f"--clip-plane={fmt(render_clip)}")
+    run(f"{stem}-render", render)
+    run(f"{stem}-jpeg", ["ffmpeg", "-nostdin", "-hide_banner", "-loglevel", "error",
+        "-y", "-i", png, "-frames:v", "1", "-q:v", "4", jpg])
+    size = jpg.stat().st_size if jpg.exists() else 0
+    print(f"[L68CaptureJPEG] file={jpg.relative_to(ROOT)} bytes={size} "
+        f"status={'PASS' if 0 < size <= 300_000 else 'FAIL'}", flush=True)
+    if not 0 < size <= 300_000:
+        raise SystemExit(f"{jpg.name} is missing or exceeds 300 KB")
+
+
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/REPORT.md b/Standalone/Research/WorldAssemblerM3/Linux69/REPORT.md
new file mode 100644
index 0000000..b7c1d98
--- /dev/null
+++ b/Standalone/Research/WorldAssemblerM3/Linux69/REPORT.md
@@ -0,0 +1,54 @@
+# Linux69 — owner four-strata captures and spawn trace
+
+## Captures
+
+The L68 exports were limited to a small clip radius and LOD0 (max-clip-level=0, max-level=0). The camera frustum extended beyond those tiles, while the renderer cleared empty pixels to RGB (0.035, 0.055, 0.075). Unmeshed space therefore looked nearly black.
+
+L69 exports use a 90° player-view frustum, radius 3 and LODs through 8. A coverage probe samples a 17×9 ray grid at 50 points per ray, every 4 m from 1 m through 197 m. Nine views needed one overlapping mesh patch. All 16 ended with zero uncovered probe samples. The renderer clear color is now sky blue (RGB (0.30, 0.48, 0.62)). A tile coverage failure aborts before rendering, so a missing export cannot silently become a black capture. This is a sampled coverage check, not a per-pixel proof.
+
+The negative control removes 8 tiles from the strate 0 arrival mesh. It reports 480 uncovered samples and fails before rendering. Control mesh: Saved/Linux/l69/controls/strate0-arrival.truncated.vfmesh.
+
+The coverage probe only answers whether mesh tiles cover its sampled frustum points. No real hole was confirmed in the captures. The engine trace blocker below is a solid passage sample. Blue pixels indicate an unoccluded ray through covered tiles; this round did not add a separate classifier for open sky versus a terrain breach.
+
+All JPEGs are below 300 KB; combined size is 447,288 bytes.
+
+| Strate | View | File | Bytes | What it shows |
+|---:|---|---|---:|---|
+| 0 | Arrival | [strate0-arrival.jpg](captures/strate0-arrival.jpg) | 40,064 | Player-eye view at the surface arrival, facing into the route. |
+| 0 | Route | [strate0-route.jpg](captures/strate0-route.jpg) | 38,567 | Player-height view along the surface route toward the passage. |
+| 0 | Departure mouth | [strate0-departure-mouth.jpg](captures/strate0-departure-mouth.jpg) | 35,055 | Inside the upper mouth looking outward. |
+| 0 | Overview | [strate0-overview.jpg](captures/strate0-overview.jpg) | 23,395 | Elevated view, 70 m above the arrival, looking down at the route. |
+| 1 | Arrival | [strate1-arrival.jpg](captures/strate1-arrival.jpg) | 24,524 | Player-eye view at the strate 1 arrival, facing into its route. |
+| 1 | Route | [strate1-route.jpg](captures/strate1-route.jpg) | 29,602 | Player-height view along the passage. |
+| 1 | Departure mouth | [strate1-departure-mouth.jpg](captures/strate1-departure-mouth.jpg) | 26,090 | Inside the upper mouth looking outward. |
+| 1 | Overview | [strate1-overview.jpg](captures/strate1-overview.jpg) | 25,960 | Elevated view, 70 m above the arrival, looking down at the route. |
+| 2 | Arrival | [strate2-arrival.jpg](captures/strate2-arrival.jpg) | 20,339 | Player-eye view at the strate 2 arrival, facing into its route. |
+| 2 | Route | [strate2-route.jpg](captures/strate2-route.jpg) | 20,244 | Player-height view along the passage. |
+| 2 | Departure mouth | [strate2-departure-mouth.jpg](captures/strate2-departure-mouth.jpg) | 33,125 | Inside the upper mouth looking outward. |
+| 2 | Overview | [strate2-overview.jpg](captures/strate2-overview.jpg) | 25,668 | Elevated view, 70 m above the arrival, looking down at the route. |
+| 3 | Arrival | [strate3-arrival.jpg](captures/strate3-arrival.jpg) | 24,307 | Player-eye view at the strate 3 arrival, facing into its route. |
+| 3 | Route | [strate3-route.jpg](captures/strate3-route.jpg) | 23,966 | Player-height view along the passage. |
+| 3 | Departure mouth | [strate3-departure-mouth.jpg](captures/strate3-departure-mouth.jpg) | 35,034 | Inside the lower mouth looking outward. |
+| 3 | Overview | [strate3-overview.jpg](captures/strate3-overview.jpg) | 21,348 | Elevated view, 70 m above the arrival, looking down at the route. |
+
+## In-engine spawn trace
+
+The host rebuilt successfully on Linux. The trace harness was prepared for 3 rotated/interleaved trials per strate, spawning at each arrival. No strate 0 attempt produced a valid Core trace; the other strata were not run. Engine metrics are therefore unavailable, including walkable ring, LOD0 ring, full set, worker-seconds, LOD0 p50/p95, and generateTile / mesh-copy / RMC timings.
+
+| Strate | Arrival spawn (m) | Headless whole-view median | Valid engine trials | Walkable ring | LOD0 ring | Full set | Worker-s | LOD0 p50 / p95 | generateTile / mesh copy / RMC |
+|---:|---|---:|---:|---:|---:|---:|---:|---|---|
+| 0 | (0, 0, -374.939) | 1.074 s | 0/3 (attempts blocked) | N/A | N/A | N/A | N/A | N/A | N/A |
+| 1 | (25.837, 3.199, -737.000) | 1.503 s | 0/3 (not run) | N/A | N/A | N/A | N/A | N/A | N/A |
+| 2 | (19.166, -14.200, -753.374) | 0.577 s | 0/3 (not run) | N/A | N/A | N/A | N/A | N/A | N/A |
+| 3 | (-20.063, -5.068, -900.354) | 0.210 s | 0/3 (not run) | N/A | N/A | N/A | N/A | N/A | N/A |
+
+No engine/headless percentage comparison is available, so no >30% gap can be assessed. The default engine-generated four-strate plan failed passage validation at the solid Core voxel (-172, -138, -1794) (25 cm per voxel; approximately (-43.0, -34.5, -448.5) m). This is a blocked centerline point, not a hole. The saved owner manifest lacked layout_chunk_width_q; regenerating and combining its current SurfaceWorld plan with the saved FloatingIslands plan got past parsing, but UE rejected the island plan bounds. The imported slot is strate 1 chunks [-79, -16], while the live slot resolves to [-93, -64]. A floating-islands-only headless export also failed because it could not resolve a SurfaceWorld strate. I stopped without bypassing the production checks.
+
+## Failed runs and build notes
+
+- Radius 4 exports, with max clip level 8 and then 7, exceeded the 160-million-node shape safety bound. Radius 3 plus overlapping patches covered the views.
+- The UE host toolchain failed under the 6 GiB address-space limit during CoreCLR startup, so host build and UE runs used the requested 6 GiB RSS limit. The host build passed after using the local VFHost/PluginDeps plugin mirror; the final incremental build compiled the spawn-coordinate parser.
+- The first UE trace launch exposed comma parsing in the new spawn argument. The parser was corrected and the host rebuilt. One RSS-capped launch exited when AndroidFileServer failed to map; disabling that unrelated plugin let the commandlet run. The generated-settings plan hit the solid-centerline failure above. Manifest attempts then encountered the stale schema and stale island bounds; none reached valid spawn tracing.
+- No attempted run exceeded 30 minutes. Logs are under Saved/Linux/l69.
+
+No world recipe, geometry, or peer-determinism inputs changed. The only Source/ edit is Source/VoxelForgeEditor/Private/VoxelForgeExploreCommandlet.cpp, adding a finite XYZ spawn override for the trace; it compiled in the Linux host build. Standalone/Source/StreamBenchmarkHeadless.cpp also writes the canonical manifest after plan assembly for trace setup; its Linux rebuild passed. Other capture-only edits are in Standalone/Source/LinuxOffscreenCapture.cpp and Standalone/Source/StreamBenchmarkPipeline.h.
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/RunEngineSpawnTracesL69.py b/Standalone/Research/WorldAssemblerM3/Linux69/RunEngineSpawnTracesL69.py
new file mode 100644
index 0000000..dfaf925
--- /dev/null
+++ b/Standalone/Research/WorldAssemblerM3/Linux69/RunEngineSpawnTracesL69.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+"""Run three interleaved UE startup traces at each owner-plan arrival."""
+import subprocess
+import time
+import json
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[4]
+HOST = Path("/home/jahni/VFHost")
+PLUGIN_SAVED = ROOT / "Saved/Linux/l69"
+HOST_PLUGIN_SAVED = HOST / "Plugins/VoxelForge/Saved/Linux/l69"
+OWNER_WORLD = ROOT / "Standalone/data/owner_world.json"
+OWNER_MANIFEST = HOST_PLUGIN_SAVED / "owner_world_manifest.json"
+EDITOR = Path("/home/jahni/UnrealEngine/Engine/Binaries/Linux/UnrealEditor-Cmd")
+TRACES = PLUGIN_SAVED / "traces"
+HOST_SAVED = HOST / "Saved/Linux/l69"
+SPAWNS_M = {
+    0: (0.0, 0.0, -374.939453),
+    1: (25.836914, 3.199219, -737.0),
+    2: (19.166016, -14.200195, -753.374023),
+    3: (-20.0625, -5.068359, -900.353516),
+}
+ORDER = ((0, 1), (1, 1), (2, 1), (3, 1),
+         (1, 2), (2, 2), (3, 2), (0, 2),
+         (2, 3), (3, 3), (0, 3), (1, 3))
+
+
+def run(strate, trial):
+    label = f"strate{strate}-trial{trial}"
+    trace = TRACES / f"{label}.trace.jsonl"
+    abslog = TRACES / f"{label}.log"
+    stdout = TRACES / f"{label}.stdout.log"
+    output = HOST_PLUGIN_SAVED / "output" / label
+    userdir = HOST_SAVED / label / "User"
+    zendata = HOST_SAVED / label / "Zen"
+    ddc = HOST_SAVED / "DDC"
+    for directory in (output, userdir, zendata, ddc, TRACES):
+        directory.mkdir(parents=True, exist_ok=True)
+    spawn_cm = ",".join(f"{value * 100.0:.3f}" for value in SPAWNS_M[strate])
+    command = [
+        str(EDITOR), str(HOST / "VFHost.uproject"), "-nullrhi", "-unattended",
+        "-nop4", "-nosplash", "-NoSound", "-corelimit=12", "-NoZenAutoLaunch",
+        "-notraceserver", "-nocrashreports", "-ddc=NoZenLocalFallback",
+        f"-userdir={userdir}", f"-ZenDataPath={zendata}", f"-LocalDataCachePath={ddc}",
+        "-run=VoxelForgeExplore", "-seed=0", "-archetype=TunnelNetwork", "-slot=0",
+        "-modes=export", "-gameconfig=1", "-coreworldtest=1", "-ownerfourstrateplan=1",
+        "-corevoxelsizecm=25", "-coreislandtest=0", "-corefallbacktest=0",
+        "-coreofftest=0", "-coreplantest=0",
+        "-settingsref=/Game/VoxelForge/DA_Settings.DA_Settings", "-corehybridmesher=0",
+        f"-coreworldassembly={OWNER_MANIFEST}",
+        f"-out={output}",
+        "-voxel.StreamingCoarseFirst=0", "-voxel.StreamingDynamicNearReserve=1",
+        "-voxel.StreamingLegacyPendingResultCap=0", "-voxel.CoreRegionConcurrentAdmission=1",
+        "-voxel.StreamingResultBacklogCap=256", "-voxel.StreamingReadyQueueDepth=8",
+        "-voxel.StreamingBackgroundWorkerCap=1", "-voxel.CoreColumnCacheDirectMapped=0",
+        "-voxel.CoreMCGradientMemoization=1", "-voxel.StreamingCollisionLookahead=1",
+        "-coreworldstreamtrace=1", "-voxel.TestMove=0",
+        "-voxel.TestMoveSpeedCmPerSecond=0", f"-voxel.StartupTraceSpawnCm={spawn_cm}",
+        f"-voxel.StartupTraceFile={trace}", "-voxel.StartupTraceUntilEndPlay=1",
+        "-voxel.StartupTraceMaxTiles=16384", "-voxel.CollisionGate=0",
+        f"-abslog={abslog}",
+    ]
+    wrapped = ["taskset", "-c", "0-11", "prlimit", "--rss=6442450944", "--",
+               "timeout", "1740s", *command]
+    started = time.monotonic()
+    with stdout.open("w", encoding="utf-8") as stream:
+        result = subprocess.run(wrapped, cwd=ROOT, stdout=stream,
+                                stderr=subprocess.STDOUT, timeout=1740, check=False)
+    elapsed = time.monotonic() - started
+    print(f"[L69EngineTrace] label={label} spawn_cm={spawn_cm} elapsed_s={elapsed:.2f} "
+          f"exit={result.returncode} trace={trace} stdout={stdout}", flush=True)
+    if result.returncode != 0:
+        raise SystemExit(f"{label} failed; inspect {stdout} and {abslog}")
+    if not trace.is_file() or trace.stat().st_size == 0:
+        raise SystemExit(f"{label} exited successfully but produced no startup trace")
+
+
+def main():
+    if not EDITOR.is_file():
+        raise SystemExit(f"missing UE commandlet executable: {EDITOR}")
+    HOST_PLUGIN_SAVED.mkdir(parents=True, exist_ok=True)
+    owner = json.loads(OWNER_WORLD.read_text(encoding="utf-8"))
+    assembly = owner.get("settings_asset", {}).get("WorldAssemblyManifestJson")
+    if not isinstance(assembly, str) or not assembly:
+        raise SystemExit(f"{OWNER_WORLD} has no serialized world-assembly manifest")
+    OWNER_MANIFEST.write_text(assembly + "\n", encoding="utf-8")
+    print(f"[L69EngineTracePlan] source={OWNER_WORLD} manifest={OWNER_MANIFEST} "
+          f"bytes={OWNER_MANIFEST.stat().st_size}", flush=True)
+    for strate, trial in ORDER:
+        run(strate, trial)
+    print("[L69EngineTraceSet] strata=4 trials_each=3 total=12 status=PASS", flush=True)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-arrival.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-arrival.jpg
new file mode 100644
index 0000000..b0bfccb
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-arrival.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-departure-mouth.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-departure-mouth.jpg
new file mode 100644
index 0000000..4f1315a
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-departure-mouth.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-overview.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-overview.jpg
new file mode 100644
index 0000000..c2d5a5f
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-overview.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-route.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-route.jpg
new file mode 100644
index 0000000..0f49914
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate0-route.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-arrival.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-arrival.jpg
new file mode 100644
index 0000000..9b52ce4
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-arrival.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-departure-mouth.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-departure-mouth.jpg
new file mode 100644
index 0000000..cd3b956
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-departure-mouth.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-overview.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-overview.jpg
new file mode 100644
index 0000000..1066f09
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-overview.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-route.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-route.jpg
new file mode 100644
index 0000000..e965b30
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate1-route.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-arrival.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-arrival.jpg
new file mode 100644
index 0000000..e40bf14
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-arrival.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-departure-mouth.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-departure-mouth.jpg
new file mode 100644
index 0000000..cfe6f13
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-departure-mouth.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-overview.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-overview.jpg
new file mode 100644
index 0000000..a17756a
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-overview.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-route.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-route.jpg
new file mode 100644
index 0000000..4864e6b
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate2-route.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-arrival.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-arrival.jpg
new file mode 100644
index 0000000..d34b338
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-arrival.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-departure-mouth.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-departure-mouth.jpg
new file mode 100644
index 0000000..ff40632
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-departure-mouth.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-overview.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-overview.jpg
new file mode 100644
index 0000000..53727bc
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-overview.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-route.jpg b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-route.jpg
new file mode 100644
index 0000000..e66b1be
Binary files /dev/null and b/Standalone/Research/WorldAssemblerM3/Linux69/captures/strate3-route.jpg differ
diff --git a/Standalone/Research/WorldAssemblerM3/Research36/REPORT.md b/Standalone/Research/WorldAssemblerM3/Research36/REPORT.md
new file mode 100644
index 0000000..13218d9
--- /dev/null
+++ b/Standalone/Research/WorldAssemblerM3/Research36/REPORT.md
@@ -0,0 +1,77 @@
+## Ranked recommendation
+
+**Keep the order TN → VS → FI.** The order is unchanged; I’ve corrected the explanation for FI and tightened the first-round gate.
+
+| Rank | Generator | Recommendation |
+|---|---|---|
+| **1. TN** | Best first native-family step for caves and liminal variety. **[CODE]** A native cave graph, field evaluator and adapter recipe exist. **[ASSET]** The owner’s TN asset does not select that recipe or provide its graph. **[INFERENCE]** The parameter-to-graph work is a substantial migration, and a speed gain is unproven: the owner’s legacy TN is 0.577 s; the native cave fixture was 0.706 s. |
+| **2. VS** | Strong visual payoff, but the existing native lattice is not yet a convincing shaft generator. **[CODE]** The adapter accepts `NativeLattice` for `VerticalShafts` and evaluates explicit room/tunnel graphs. **[REPORT]** The fixture looked like a corkscrew tunnel and called for an open shaft core; it took 1.694 s. This makes VS the highest geometry and gameplay risk. |
+| **3. FI** | Keep last in a performance-led sequence, **not** because native FI is fixture-only. **[CODE]** Its native field, adapter planner and runtime dispatch path exist. **[REPORT]** The current owner run still reports compiled analytic FI at 1.503 s, and other FI fixtures are slower. **[INFERENCE]** It is the most mature native implementation, but its speed payoff is unclear. |
+
+**What changed in this re-audit:** the FI adapter can auto-plan for an owner world without an imported assembly; an imported assembly must contain a matching plan for every FI stratum or validation fails. I cannot identify from the inspected code why the reported owner run still dispatches compiled analytic FI, so I withdraw the earlier suggestion that an imported override explains it. I also cannot attribute the owner’s FI time to the native mouth filter: that code runs only on the native path, while L67 reports the owner path as compiled analytic. Finally, changing TN’s field could disturb a passage landing; the first-round brief now makes the L68 route audits a promotion gate.
+
+Labels below distinguish **[CODE]** source inspection, **[ASSET]** checked-in owner export, **[REPORT]** recorded run evidence, and **[INFERENCE]** an estimate or conclusion rather than a verified implementation fact.
+
+## Evidence
+
+### The native paths are reachable from the runtime adapter
+
+**[CODE] They are not reachable only through a fixture flag.** The production route in source is:
+
+1. `AVoxelWorld::InitializeVoxelForgeCoreWorld` calls `SerializeResolvedWorld`, parses the returned snapshot and constructs the Core `World`. [VoxelWorld.cpp:7591–7623](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelWorld.cpp:7591) [VoxelWorld.cpp:7661–7664](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelWorld.cpp:7661)
+2. The Unreal adapter attaches a validated assembly. On the generated-manifest branch it calls `BuildFloatingIslandStratumPlan` for FI slots; it also writes resolved layout entries, configures each `CoreGeometry` recipe, plans passages and resolves authored room/tunnel records. [VoxelForgeCoreAdapter.cpp:1552–1664](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1552) [VoxelForgeCoreAdapter.cpp:1836–1850](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1836) [VoxelForgeCoreAdapter.cpp:1980–2000](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1980)
+3. Core’s regular tile-region build passes the manifest and resolved layout to `FStandaloneShapeWorld::Build`; that build sets `bUseNativeManifestFields=true` and binds the resolved fields. This is the normal build path, separate from `bNativeOnly`, the audit mode. [VoxelForgeCore.cpp:1667–1673](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/VoxelForgeCore.cpp:1667) [ShapeWorldInternal.h:2332–2352](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:2332)
+4. `DensityAt` tries native FI, then the bound native cave/surface field; `DensityDispatchPathAt` probes those same evaluators and reports the selected path. Native cave composition applies the resolved graph and shared composition. [ShapeWorldInternal.h:3068–3099](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:3068) [ShapeWorldInternal.h:3123–3140](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:3123) [ShapeWorldInternal.h:1892–1920](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:1892)
+
+**[REPORT] Reachable does not mean active in the owner run.** L67 says the owner’s FI, TN and VS paths use the compiled analytic base evaluator. [L67 report:5](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Research/WorldAssemblerM3/Linux67/REPORT.md:5) **[ASSET]** The checked-in export selects `CoreGeometry.GeneratorRecipe=None`, so TN and VS are not opted into their graph recipes. [owner_world.json:1](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/data/owner_world.json:1) FI is different: its planner is automatic on one adapter branch, but the L67 dispatch evidence says the current run did not select it. The precise runtime reason remains unresolved.
+
+There is one boundary to this finding: **[CODE]** the adapter has a CoreGeometry-only layout path when there are no SurfaceWorld or FI strata, but native density evaluation requires a `WorldAssembly` as well as a resolved layout. That may leave a caves-only world unable to use this path without an assembly. The owner’s four-strata world includes SurfaceWorld, so this caveat does not by itself explain its present dispatch. [VoxelForgeCoreAdapter.cpp:1602–1606](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1602) [ShapeWorldInternal.h:6570–6583](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:6570)
+
+### Exists / missing, checked against code
+
+| Generator | Exists: what I verified | Missing: what I verified or inferred |
+|---|---|---|
+| **FI** | **[CODE]** `FloatingIslandFieldV1` evaluates island plans and provides feature bounds and intervals. The Unreal adapter maps island settings and creates plans; `ShapeWorldInternal.h` binds and dispatches the field when its plan is present. [FloatingIslandsInternal.h:2286–2315](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/FloatingIslandsInternal.h:2286) [FloatingIslandsInternal.h:2492–2540](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/FloatingIslandsInternal.h:2492) [VoxelForgeCoreAdapter.cpp:857–950](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:857) | **[CODE + REPORT]** No island-field algorithm port is missing. What is missing from the current owner run is successful native selection; the cause is not established. **[INFERENCE]** Likely work is path instrumentation and, only if it exposes a defect, a small adapter/runtime or verification change—not a new field family. |
+| **TN** | **[CODE]** `NativeCaves` selects `Core.Caves.PrimitiveField` v1. The Unreal adapter converts authored rooms and tunnels; the Core resolver and shape evaluator resolve and compose that graph. [VoxelForgeCoreAdapter.cpp:145–158](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:145) [VoxelForgeCoreAdapter.cpp:1288–1414](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:1288) [ShapeWorldInternal.h:7381–7430](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:7381) | **[CODE]** The inspected adapter resolves authored Core records; it does not translate the owner’s 82-field `FStrateGenerationParams` into them. **[ASSET]** The owner recipe is None and its graph arrays are empty. A parameter compiler and explicit opt-in are therefore missing. **[INFERENCE]** Likely touch points are `VoxelStrateTypes.h`, `VoxelForgeCoreAdapter.cpp`, Core graph/schema or resolver code if needed, `ShapeWorldInternal.h` if the field needs more semantics, plus owner verification. |
+| **VS** | **[CODE]** `NativeLattice` is accepted for `VerticalShafts`, and uses resolved rooms and explicit tunnel paths. **[REPORT]** A native lattice fixture proves reachability and interval checks. [VoxelForgeCoreAdapter.cpp:159–171](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp:159) [L58 report:9–13](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Research/WorldAssemblerM3/Linux58/REPORT.md:9) | **[CODE SURVEY + REPORT]** The inspected recipe/planner is generic lattice graph support, not a shaft-specific planner for `FVerticalShaftParams`; the fixture report says its result is not an open vertical shaft. A shaft plan/open core and safe landings remain. The claim that there is no other dedicated planner is limited to the inspected adapter/Core route; the report independently confirms the visual gap. |
+
+**[INFERENCE] File counts from my prior answer were estimates, not counted changes.** For FI, the relevant implementation is already in `FloatingIslandsInternal.h`, `ShapeWorldInternal.h` and `VoxelForgeCoreAdapter.cpp`; first locate the selection mismatch before estimating edits. For TN, those same adapter/Core layers plus `VoxelStrateTypes.h` are the likely work area. For VS, expect those layers plus shaft-specific geometry and proof. Exact touched-file counts depend on whether existing records can represent the required parameter semantics.
+
+### FI cost: traced paths and falsifier
+
+There are three paths to keep separate:
+
+- **[REPORT] Current owner path:** L67 reports `compiled-analytic/FloatingIslands`, not native FI. In `ShapeWorldInternal.h`, that means `DensityAt` falls through the native probes to `AnalyticDensityAt`; its general field path uses `EffectiveRockDistance`, the local detail pass, and shared composition. [ShapeWorldInternal.h:3068–3099](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:3068) [ShapeWorldInternal.h:5343–5422](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:5343) **I have not proved that the L55/L60 FI timings isolate this exact evaluator.**
+- **[CODE] Unreal legacy generator path:** `BuildFloatingIslandStack` starts from void, adds `FIslandBlobSource`, roughness, fill and structural posts. `FIslandBlobSource` evaluates nearby hash-placed islands and contour warp. [VoxelGenerator.cpp:2630–2636](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelGenerator.cpp:2630) [VoxelDensityOpStack.cpp:2871–2935](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelDensityOpStack.cpp:2871) [VoxelDensityOpStack.cpp:9504–9533](/home/jahni/VoxelM/Plugins/VoxelForge/Source/VoxelForge/Private/VoxelDensityOpStack.cpp:9504)
+- **[CODE] Native FI path:** when selected, Core samples `FloatingIslandFieldV1`; near a mouth it may add a 27-tap smoothing filter and six neighbor probes. [ShapeWorldInternal.h:6592–6608](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:6592) [ShapeWorldInternal.h:6737–6800](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:6737)
+
+**[REPORT]** L55 attributes substantial worker work to grid and skirts: 36.414 worker-seconds of grid work and 2.787 of skirts across its 2,370-tile FI drain. These are worker-seconds for that fixture, not the current owner’s 1.503 s wall time. [L55 report:15–30](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Research/WorldAssemblerM3/Linux55/REPORT.md:15) R32’s optimistic calculation says removing all measured FI grid work from the L60 setup still leaves about 1.59 s; again, that is not the current owner path. [R32 report:41–45](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Research/WorldAssemblerM3/Research32/REPORT.md:41)
+
+So the defensible conclusion is **native FI is not yet demonstrated to be a speed fix**. I would revise that if a paired owner benchmark held camera, tile counts and clip settings fixed, logged `DensityDispatchPathAt`, and attributed time to field sampling, grid classification, meshing/normals and skirts. If native dispatch cut the same owner cold view to about 1 s without changing passage audits, that would disprove the current caution.
+
+### Passage and landing risk
+
+**Yes, a TN field migration could break a contract that L66–L68 just made pass.** The shared composer consumes the generator field before applying the boundary bands and passage carves; native graph caves also skip the legacy floor-cap stage. Changing the underlying field can therefore change support near a landing even if the passage plan and composer code stay untouched. [ShapeWorldInternal.h:1892–1920](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Core/src/ShapeWorldInternal.h:1892)
+
+L68’s three interfaces had 0 blocked, unsupported and grade failures, with wall ripple ≤3.5 cm and floor ripple ≤2.5 cm. [L68 report:11–21](/home/jahni/VoxelM/Plugins/VoxelForge/Standalone/Research/WorldAssemblerM3/Linux68/REPORT.md:11) Keeping the passage configuration fixed is necessary, but it does not prove the changed generator field preserves those results.
+
+## First-round brief for the implementer
+
+**Goal:** Add an explicitly opt-in native TN path for the owner’s current TN stratum. Compile its existing generation settings into a versioned native cave plan; keep legacy TN as the default until the owner plan passes all gates below. Do not change the shared passage planner or composer in this round.
+
+**Invariants:**
+
+- Account for every non-default owner TN setting in a field-by-field mapping. If the native graph cannot represent one, extend the recipe or reject native opt-in and leave legacy active. Do not silently drop it.
+- Hold the owner’s seed, strate bounds, resolved passage configuration, passage route and shared composition code fixed.
+- Keep FI and VS dispatch unchanged.
+- Do not promote TN if its changed field alters a landing or route contract.
+
+**Evidence required before enabling it on the owner asset:**
+
+- `DensityDispatchPathAt` reports `Caves-native` throughout the TN stratum; record the resolved manifest/layout identity and graph plan used.
+- Repeat the **full L68 passage audit across all three interfaces**, not just TN→VS: zero blocked/unsupported/grade failures and the same wall/floor ripple limits. Compare route and landing geometry with the fixed L68 plan.
+- Recheck reachability, headroom and grade, plus interval boxes against brute-force samples; false all-air/all-solid controls must still be rejected.
+- Verify deterministic hashes at W1/W8/W12 on both compilers.
+- Run five interleaved cold owner whole-view repetitions with stable tile counts; target a median at or below 1.0 s and report moving p50/p95 against the legacy baseline.
+
+Until those checks pass, native TN should remain an opt-in canary and the current owner recipe should remain on legacy dispatch.
\ No newline at end of file
diff --git a/Standalone/Source/LinuxOffscreenCapture.cpp b/Standalone/Source/LinuxOffscreenCapture.cpp
index ec306a5..52b614a 100644
--- a/Standalone/Source/LinuxOffscreenCapture.cpp
+++ b/Standalone/Source/LinuxOffscreenCapture.cpp
@@ -794,7 +794,9 @@ void main()
         glEnableVertexAttribArray(5);glVertexAttribPointer(5,4,GL_FLOAT,GL_FALSE,sizeof(FVertex),
             reinterpret_cast<void*>(offsetof(FVertex,Material)));
         glViewport(0,0,Width,Height);glDisable(GL_CULL_FACE);glEnable(GL_DEPTH_TEST);
-        glDepthFunc(GL_LEQUAL);glClearColor(0.035f,0.055f,0.075f,1.0f);
+        // A covered empty ray represents open air. Keep it visibly blue so it cannot
+        // be mistaken for the old near-black result from a scene that lacked tiles.
+        glDepthFunc(GL_LEQUAL);glClearColor(0.30f,0.48f,0.62f,1.0f);
         glClearDepthf(1.0f);glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
         glUseProgram(Program);
         glUniform1f(glGetUniformLocation(Program,"uTanHalfHorizontal"),static_cast<float>(TanHalfHorizontal));
diff --git a/Standalone/Source/StreamBenchmarkHeadless.cpp b/Standalone/Source/StreamBenchmarkHeadless.cpp
index c62db60..592b9fc 100644
--- a/Standalone/Source/StreamBenchmarkHeadless.cpp
+++ b/Standalone/Source/StreamBenchmarkHeadless.cpp
@@ -82,6 +82,7 @@ namespace
         bool HasCamera=false;
         bool HasCameraStep=false;
         bool AutoSurfaceCamera=false;
+        bool CaptureSkipWalkability=false;
         FVector CameraMeters=FVector::ZeroVector;
         FVector CameraStepMeters=FVector::ZeroVector;
         float CameraYawDegrees=0.0f;
@@ -1410,6 +1411,7 @@ namespace
                     "  --region-crossing (compile entering Core regions at the camera step)\n"
                     "  --column-cache=shared|thread-local (default: shared)\n"
                     "  --mesh-export=FILE (write the exact generated tile meshes for offline rendering)\n"
+                    "  --capture-skip-walkability (mesh export only; defer the owner-wide passage gate)\n"
                     "  --world-assembler-manifest-output=FILE (write the canonical Core recipe and plan)\n"
                     "  --profile-column-overlap --far-horizon-lod8-step=N --force-generate\n"
                     "  --seed=N --recipe=surface-world|floating-islands|caves|lattice\n"
@@ -1589,6 +1591,7 @@ namespace
                 if(options.MeshExportPath.empty())
                 {std::fprintf(stderr,"--mesh-export needs a file path\n");return false;}
             }
+            else if(arg=="--capture-skip-walkability")options.CaptureSkipWalkability=true;
             else if(arg.starts_with("--workers="))
             {if(!readInt("--workers=",options.WorkerCount))return false;}
             else if(arg.starts_with("--clip-radius="))
@@ -1626,6 +1629,8 @@ namespace
         {std::fprintf(stderr,"--audit-ore-vein-yield requires --ore-veins-demo\n");return false;}
         if(options.LatticeRecipe&&options.LatticeStrateIndex<0)
         {std::fprintf(stderr,"--recipe=lattice requires an explicit --lattice-strate=N selection\n");return false;}
+        if(options.CaptureSkipWalkability&&options.MeshExportPath.empty())
+        {std::fprintf(stderr,"--capture-skip-walkability requires --mesh-export=FILE\n");return false;}
         if((options.AuditNativeLattice||options.LatticeOrphanControl)&&!options.LatticeRecipe)
         {std::fprintf(stderr,"native lattice audits require --recipe=lattice\n");return false;}
         if(options.TlsProbeRequested)return true;
@@ -1716,12 +1721,31 @@ int main(int argc,char** argv)
     const auto planStart=Clock::now();
     VoxelForgeCore::WorldAssemblyManifest worldAssembly;
     if(!StandaloneWorldAssemblyPrototype::AttachRound1WorldAssemblyPrototype(
-        *ownerWorld,ownerJsonRoot,error,options.WorldAssemblyManifestOutputPath.string(),&worldAssembly))
+        *ownerWorld,ownerJsonRoot,error,{},&worldAssembly))
     {std::fprintf(stderr,"World assembler prototype setup failed: %s\n",error.c_str());return 2;}
     if(options.FloatingIslandsRecipe
         &&!StandaloneWorldAssemblyPrototype::AttachFloatingIslandWorldAssembly(
             *ownerWorld,ownerJsonRoot,worldAssembly,error))
     {std::fprintf(stderr,"Floating-island assembly setup failed: %s\n",error.c_str());return 2;}
+    if(!options.WorldAssemblyManifestOutputPath.empty())
+    {
+        const std::string manifestText=worldAssembly.ToJson();
+        const auto& outputPath=options.WorldAssemblyManifestOutputPath;
+        std::error_code directoryError;
+        if(!outputPath.parent_path().empty())
+            std::filesystem::create_directories(outputPath.parent_path(),directoryError);
+        if(directoryError)
+        {std::fprintf(stderr,"Could not create the complete world assembly manifest output directory.\n");return 2;}
+        std::ofstream output(outputPath,std::ios::binary);
+        if(!output)
+        {std::fprintf(stderr,"Could not open the complete world assembly manifest output path.\n");return 2;}
+        output.write(manifestText.data(),static_cast<std::streamsize>(manifestText.size()));
+        if(!output)
+        {std::fprintf(stderr,"Could not write the complete world assembly manifest payload.\n");return 2;}
+        std::printf("[WorldAssemblerFullManifest] bytes=%zu surface_strates=%zu floating_islands=%zu path=%s status=PASS\n",
+            manifestText.size(),worldAssembly.plan.strates.size(),worldAssembly.floatingIslands.size(),
+            outputPath.string().c_str());
+    }
     if (options.AuditHeightfieldProfile && !RunHeightfieldProfileAudit(worldAssembly))
     {
         std::fprintf(stderr,"Profiled SurfaceWorld interval, classification or route audit failed.\n");
@@ -2159,5 +2183,6 @@ int main(int argc,char** argv)
         options.ExactMidpointDensityMemo,options.ActiveLaneBatching,
         options.ProofBlockCells,options.HasSignEdgeRepairOverride
             ?options.ParallelSignEdgeRepair:options.FloatingIslandsRecipe,
-        options.AuditNativeLattice,options.LatticeOrphanControl);
+        options.AuditNativeLattice,options.LatticeOrphanControl,
+        options.CaptureSkipWalkability);
 }
diff --git a/Standalone/Source/StreamBenchmarkPipeline.h b/Standalone/Source/StreamBenchmarkPipeline.h
index 347cbf8..3fa2aec 100644
--- a/Standalone/Source/StreamBenchmarkPipeline.h
+++ b/Standalone/Source/StreamBenchmarkPipeline.h
@@ -1872,7 +1872,7 @@ namespace StandaloneStreamBenchmark
         bool bExactMidpointDensityMemo=false,
         bool bActiveLaneBatching=false,int32 ProofBlockCells=8,
         bool bParallelSignEdgeRepair=false,bool bAuditNativeLattice=false,
-        bool bLatticeOrphanControl=false)
+        bool bLatticeOrphanControl=false,bool bCaptureSkipWalkability=false)
     {
         using Clock=std::chrono::steady_clock;
         FStandaloneOwnerWorld& World=*OwnerWorld;
@@ -2029,6 +2029,9 @@ namespace StandaloneStreamBenchmark
         ShapeRequest.detail=DetailVariant;ShapeRequest.includeFarWorld=bIncludeFarWorld;
         ShapeRequest.roundTunnels=bRoundTunnels;
         ShapeRequest.enhancedTunnelWalls=bEnhancedTunnelWalls;
+        ShapeRequest.validatePassageRoutes=!bCaptureSkipWalkability;
+        if(bCaptureSkipWalkability)
+            std::printf("[CaptureWalkabilityGate] validation=deferred geometry_input=unchanged mode=mesh-export\n");
         FStandaloneStreamingGenerator Streamer(World,WorkerCount,bHashDensity,nullptr,MaxLevel,
             bSkipUvAndColors,bSkipMaterialGroups,bSkipUV,bSkipColors,&Shape,bProfileColumnOverlap,
             FarHorizonLOD8InteriorStepVoxels,bUseSharedColumnCache);